Where did part of the "myth of frontier" idea begin

Explanation :The frontier myth or myth of the West is one of the influential myths in American culture. The frontier is the concept of a place that exists at the edge of a civilization, particularly during a period of expansion. The American frontier occurred throughout the 17th to 20th centuries as European Americans colonized and expanded across North America. This period of time became romanticized and idealized in literature and art to form a myth. Richard Slotkin, a prominent scholar on the subject, defines the myth of the frontier as "America as a wide-open land of unlimited opportunity for the strong, ambitious, self-reliant individual to thrust his way to the top.

yes i think there would be volunteers